The invention relates to an intake air compressor for an internal combustion engine including a compressor wheel disposed in the air intake duct and an adjustable inlet guide vane structure for controlling the airflow to the compressor.
DE 199 55 508 C1 discloses an exhaust gas turbocharger for an internal combustion engine, which comprises an exhaust gas turbine in the exhaust gas duct and a compressor in the air intake duct of the internal combustion engine. The exhaust gas turbine is driven by the pressurized exhaust gases of the engine, the rotation of the turbine wheel being transmitted by a shaft to the compressor wheel, which compresses combustion air sucked from the environment to an increased boost pressure, at which the combustion air is fed to the cylinders of the internal combustion engine. In order to improve the transient behavior of the exhaust gas turbocharger, the compressor has, parallel to the compressor inlet duct, an auxiliary duct, which joins the compressor inlet duct in the area of the compressor wheel, an adjustable guide vane structure being disposed in the entrance area to the compressor wheel. At low loads and rotational speeds, in particular, the flow cross section in the compressor inlet duct can be reduced or shut off and the combustion air which is to be supplied can be conducted to the compressor wheel via the auxiliary duct. The combustion air passes through the flow guide structure and undergoes a swirl, under which the combustion air strikes the compressor wheel and imparts to the latter a driving momentum. This mode of operation of the compressor is also referred to as cold air turbine operation.
Based on this prior art, it is the object of the present invention to provide a compressor for an internal combustion engine in such a way that the compressor speed can be kept at a high level, even at low engine speeds and engine loads. Expediently, the air flow through the compressor is to be accurately controlled by simple design measures.